In a 3rd Generation Partnership Project (3GPP) network, a Long-Term Evolution (LTE) portion of the network supports only data packet (or packet-switched (PS)) services. A Universal Mobile Telecommunications System (UMTS) portion of the network and a Global System for Mobile Communications (GSM) portion of the network may support circuit-switched (CS) services. When a voice call is initiated, the network may cause the call to be transferred from the PS portion of the network to the CS portion of the network. Transferring a call in this manner is often referred to as a CS Fallback Procedure (CSFB).